you're catching this in a completely naturalistic environment. you don't know -- there's a lot of things. you don't know exactly how it's going to go. we set up everything and then as the pilots and parachuters were planning their execution, we had to hope that what they said they were going to do would come in and all work right. you'll see in the show a lot of stuff went wrong. >> dr. barth, i have to say, i've been somewhat fatalistic when i ride an airplane. why put on a seat belt? come on. no one is surviving this crash but that's not true. you say people survive plane crashes at an incredibly high rate? >> most people survive plane crashes and most plane crashes are survivable. >> because of where they've chosen to do, where they've chosen to sit? why do they survive? >> a whole lot of factors go into that, but part of it is being aware of where your exits are and what you're going to do to survive. some are dependent on the crash. the first ten rows were destroyed. >> oh, first class. >> sit in the way back. >> cindy measured the potential